A risk factor is something that increases your likelihood of getting a disease or condition.

It is possible to develop
autism
with or without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing autism. There is no way known to modify your child's risk for autism.

Genetic Factors

Genetics is believed to play a role in the risk of autism because the condition is more common in:

Families

Identical twins

Recent studies have linked deletions in a section of chromosome 16. This chromosome abnormality may account for a small percentage of autism cases.

Gender

Caucasian males are more likely to be affected by autism than females. When girls are affected, though, they may have more profound symptoms.

Age of Parents

Older parents (eg, mother's age over 35) may have a higher risk of having a child with autism.

Medical Conditions

Autism occurs more frequently in children with rare genetic disorders or other medical conditions, including:

Tuberous sclerosis—A rare, multi-system genetic disease that causes benign tumors to grow in the brain and on other vital organs such as the kidneys, heart, eyes, and skin. It commonly affects the central nervous system and results in a combination of symptoms including
seizures
, developmental delay, behavioral problems, skin abnormalities, and
kidney disease
.

Fragile X syndrome
—A hereditary disorder of the X chromosome. It is the most common cause of inherited intellectual disability.

Neurofibromatosis
—A genetic disorder of the nervous system. It causes tumors to grow on the nerves in any part of the body. Neurofibromatosis can also produce other abnormalities, such as changes in the skin and deformed bones.

Problems during pregnancy or delivery, including
rubella
—Rubella is a mild, highly contagious illness that is caused by a virus. It is characterized by a rash, swollen glands, and joint pain. If a pregnant woman has rubella, it can cause birth defects in her baby.
Other possible risk factors include breech delivery and birth at less than 35 weeks gestation.

Epilepsy
—The term “epilepsy” refers to any disorder characterized by recurrent seizures. During a seizure, you may lose consciousness, stare into space, have convulsions (abnormal jerking of the muscles), or experience abnormalities of sensation or emotion.

Birth defects—Birth defects may also predispose a child to developing autism.

There has been a lot of press attention claiming links of vaccines and the vaccine preservative thimerosol as being risk factors for autism. Studies, though, have not found an association between vaccines and the development of autism.

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY.
Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.